Pressure switch



Oct. 27, 1953 H H. woLFE ETAL PRESSURE SWITCH 5 Sheets-Sheet l Original Filed April 27, 1948 Oct. 27, 1953 H H, WOLFE UAL 2,657,289

PRESSURE SWITCH Original Filed April 27, 1948 3 Sheets-Sheet 2 mvENToRs H. mx. woLFE EDWARD W. HA S B/Mwjjw ATTORNEYS Oct. 27, 1953 H H. woLFE ETAL PRESSURE SWITCH 5 Sheets-Sheet Z5 Original Filed April 27, 1948 INVENTORS H. HIX, WOL FE E DWARD w. HAAS BY .fj

ATTO R N EYS Patented ct. 27, 1953 UNITED STATES PATENT OF-'F'IGE assignors/to TheDayton'Pump &A`Manu"factur gigi Company, "Dayton, Ohio, a corporation of Original application April 27, 1948, Serial No. V23,536, jnow .Patent ,.No. 2,623,963, Vdated De cember .30,V v1495,22. l.Divided fand this application February 20, 1951,.SerialNoL2I1g938 Thisinvention relates to pressure switches and `to improvements therein, and isiparticularly con- 'cerned with the types of pressure switches vwhich vare used on water pumping systems and the'like.

y'This application is a division of our prior cohave rollers and vcams and similar mechanisms which have an inherent `amount of friction lthat `materially.detracts'from'the'accuracyiwithwhich the switch 'can be adjustedto open or close 'at any predetermined pressure.

The 'primary obj ect of 'the presentv invention vis to provide `an limproved pressure switch A"of rthe type referred to above 4andl which Jovercomes 'the obj ectionable features of 'the'ordi'nary typepressure switch.

It 'isanotherv object of this inventiontogprovide an improvedpressure'switch constructedof'a relatively `few "number of parts v'and 'being rsubstanrtiallyY free of lfrictional `engagement'of'the moving parts with 'each other.

These and other objects and 'advantages will i `vbecome moreapparent upon'reference to 'the'fol- "lowing description `vtaken in connection with the accompanying 'drawings in which:

Figure l is a vertical section takenthrough the switch of this invention and'showing it'with the contacts in open position.

Figure 2 is 'a View similar to Figure'lbutshowingthe contacts of vthe switch v'inl closed position.

Figure v3 is a' viewrsimilartoFigureZ'but with 'the contact 'portion 'of "the switch removed in Orderb'etter to'sh'ow'the pressure responsive actuator 'for "the switch.

`Figure 4 is a plan `View looking down on rthe actuator mechanism shown in Figure Vf3.

Figure `5 lis '-a" vertical VV'section indicated bythe y -line 5--5-on Figure v2.

Figure 6 isla'perspective view of the actuator mechanism; and

'Figure 7 is a `perspective view showing 'the ymember which transmits 'thrust v from the @pres- `sureY diaphragm Ito the actuator mechanism;

Referring to the drawings, the switch according to this invention'generallycomprises-a 'part indicated at I which lis the `pressure responsive portion of the assembly, a partindicated at l?, which is the actuator yportion or" the assembly, and aportion indicated at i4 which isthe termina'l block and contact assembly.

'These several 'parts are assembledtogetherand are "then 'enclosed with a casing 'IE -which includes the removable cover it?. "The entire Aassem- 'blyis then ready to 'be connected .to vthe electric .lines tofbe controlled'by .the switch and thepressure .part Iii can ybe connected with the source 0of pressure which is to eiTect .thesaidcontrol.

Referring -to the aforementioned pressure part .t,.thiswili be seen to comprise 1a bottom-or base part 2t having a threadedopening 22 that :receives apressurepipe, as, for'example, the pressure line `leading 'froma fpump tothe reservoir.

"The upper portion ofthe base part 12) has a .machined peripheral "ange fand against this ilange there is the `flexible diaphragm 2d. The 4diaphragm isretain'ed in 'positionby the screws 2t which extend through 'the `member "at andthe periphery of the flange and into engagement with 'a :plate `28.

The lower portion of the'casing 'i 6 is turned 1in asindicated at 3i? a'ndvisclampe'd between the periphery of the plate and the marginal portion of Jthe diaphragm `2`4. Resting on top of 'the diaphragm "2'4'is an actuator piate which v has ,arms .34 extending upwardly "from each side thereof and extending through the openings St in the plate'f. The member 32 and the arms S4 are for the purpose of transmitting thrust yfrom -the diaphragm 2:3 to the switch actuator .mechanism .at l2.

.Referring to .the .actuating mechanism, Vthis .w1ll loe-seen to comprise a bracket member fie .mounted on the `plate v28 vby the -rivets Se and having the spacedupstandingarms llt at one end and the more Widely'fspaced @standing-arms yat the other end.

Thesaid arms are .notched on'their inside edges as indicated at ii4 and a pair of bifurcated or U- shaped plates .are arranged to have theirlegs en gaged by the said-notches. As-.showrna rstplate 46`is arranged so that the ends of itslegs is lare `engaged by the notches 44 in-the upstanding arms 48. Similarly, :a second plate is arranged -to 4have the ends-of its legs 52-engaged by the notch* ves'inthe upstandingarms 42.

It-,Will be noted that theplate 50 issubstantially larger than the plate 46 and extending 3 completely around the upstanding arms llt', and that each of the legs 52 thereof have the V- shaped recesses therein and which are positioned to be engaged by the V-shaped upper ends of the arms 34 upstanding from the plate 32.

Having its head positioned beneath the plate 28 and extending upwardly through an aperture 56 in the closed end of the plate 5e is a bolt 58. A spring 6i] surrounds the bolt and bears at its lower end on the top of the plate 5!) and at its upper end beneath the washer 52, which is adjustably retained on the upper end of the bolt '58 by the adjusting nut G4.

interconnecting the plates l5 and 5S is a tension spring E6, and it will be observed that the said tension spring is positioned so as to continuously urge the said plates toward engagement with the notches in their supporting arms.

The general arrangement of the aforementioned plates, springs and associated parts is best illustrated in Figures 3, 4 and 6.

Turning now to the contact and terminal block Ill of the switch, this will be seen in Figures 1, 2 and 5 to comprise a block 1li of insulating material and which has extending therein from one side a pair or recesses "52. The recesses "i2 are substantially rectangular and extending into each end of each of the recesses is a stationary contact plate 14. Each of the contact plates 'M is connected with a rod 16 which extends transversely through the block 10 to the side opposite the recesses therein and receives a screw 18. The screw 18 is for the purpose of connecting the electric leads 80 to the said rods, and as will be noted in Figure l the leads are brought into the ends of the rods through grooves or slots 82 in the adjacent side of the block 10.

Disposed in each of the recesses 'l2 between the bottom thereof and the stationary contact plate 14 are the movable contact plates 3:1. These plates are adapted for bridging the stationary contact plates when in their Figure 2 position and for interrupting the electrical connection between the plates when in their Figure l. position.

The movable contact plates are guided and actuated by the blades B of insulating material which extend through the plates Ed and into the recesses 8B or" the block le. A spring 9i! surrounds each of the blades Se and continuously urges the associated movable contact plate toward its contact making position.

Each of the blades S6 is shouldered as at 92 and thus when moved upwardly engages the associated movable contact plate and lifts it from its contact making position. The blades 35 extend beyond the limits oi the block lll and there is a cover plate 94 which closes the recess 12 and also retains the blades ce in position.

The block 'm together with its contacts, contact actuating blades, and cover plate 94, is mounted in position on the actuator l2 by means of the screws SB which extend through the said block and cover plate and into the turned back tabs 9S and lili) which are integral with the bracket 38.

In Figures 1, 2 and 5 it will be noted that there is an adjustable screw m2 extending outwardly from the block 16J on the actuator side thereof. This screw is adjustable by means of a socket head therein from the top of the block and serves as a stop for limiting the maximum upward movement of the plate fit, as will be seen in Figure 1 wherein the plate and screw are shown in engagement.

The screw also serves to adjust the pressure differential within which the switch operates, because the closer the screw stops the palte 45 to a horizontal position the smaller the drop in pressure required beneath the diaphragm 24 to allow the said plate to return to its Figure 2 position.

In operation, the switch can be assumed normally to have all of its parts shown in the Figure 2 position. At that time the pressure at which the switch will operate is set by means of the nut lili. Thereafter the switch will remain in its Figure 2 position until pressure builds up beneath the diaphragm Erl and moves the plate 32 upwardly and the arms 34 cause the plate 50 to rotate clockwise about its pivotal connection with the upstanding arms 42.

The setting of the spring Btl determines the amount of pressure required to so move the plate 50. When the plate 5t? is moved upwardly until the line oi action of the spring is above the engagement of the legs oi the plate l5 of the upstanding arms 35s, the said plate il@ will snap upwardly to its Figure l position and bring about a quick opening of the switch contacts. Thereafter the switch will remain open until the pressure beneath the diaphragm drops to the point where the plate lili will move downwardly and again snap the plate downwardly.

As mentioned before, the pressure at which the switch will open can be adjusted by the nut "54 and the pressure differential, that is, the amount which the pressure must drop beneath the diaphragm it before the switch again closes, can be adjusted the screw m2. Both the nut and screw are available from the top of the switch merely by removing the cover member I8.

lt will be apparent that the switch has substantially no friction due to the pivotal arrangement of the plates 'i6 and 553 and thus can be adjusted as to operating pressure very accurately. Furthermore, a minimum of assembling operations are necessary because the switch part I4 is merely assembled and then is retained in assembled position by the same means which secures it in place on the bracket of the actuator. Similarly, in the actuator the two plates 4S and are retained in position by the same spring which causes the plate to snap over center.

It will be apparent that the construction of the switch is inexpensive and that the assembly thereof is quite simple, and servicing and repair of the switch can easily be done at any time.

It will be understood that this invention is susceptible to modication in order to adapt it to diierent usages and conditions and, accordingly, it is desired to comprehend such modications within this invention as may fall within the scope of the appended claims.

We claim:

1. In a pressure switch; a toggle actuator comprising a bracket having spaced pairs oi upstanding arms, the arms of each pair being spaced differently than the other pair, each said pair of arms having notches in their edges opening toward the other pair of arms, a first bifurcated plate having the ends of its legs in the notches of one pair of arms, a second bifurcated plate having the ends of its legs in the notches of the other pair of arms and extending around said first pair or" arms, a tension spring connecting the closed ends of said plates, a compression spring acting on the closed end of said second plate for urging the toggle toward one of its operative positions, other arm means upst'anding yfrom sais yplacket,and switehineans fmoutedfon said other arm means fand positioned t'obe o'pe'r- 'ated by said irst plate -when "said second 'p'l'ate fsaid rst plate in a predeterminedposition'when the plates are moved Vagainst said compression fspring, and `said stop being adjustable from v'the Vtop of said switch.

i2. In a pressure switch; `ato'gg'leactuator coin- :prising abracket'havingspaced p'airsfof upstanding arr/1s, the arms of each pair beingf'spaced difierently than the other pair, each 'said "pair of arms having notches Viii-their 'edges openin'gtoward the other pair of arms, a first bifurcated plate rhaving the ends of itsilegs in -thenotche`s tof 4one pair of arms, a second bifurcatedpl'ate having the ends of its legs in the'notches ofthe other pair-of and extending around said irstpair or arms, a tension springconnectin'grthe closed ends of said plates, a compression ispringfa'cting on the ciosed end of said second plate for urging the toggle toward one of its operative positions,

other arm means upstanding from said bracket,

a terminal block mounted on said other arm means and switch means mounted in said terminal block and positioned to be operated `by said first plate when said second plate is moved against lthe thrust of said compression spring, spring means yieldably urging said switch means towards its closed position and means for adjusting the pressure differential between said compression spring and said spring means whereby predetermined amounts of pressure are required to open and close said switch means.

3. n a pressure switch, a toggle actuator comprising a bracket having spaced pairs oi upstanding arms, the arms of each pair being spaced differently than the other pair, each said pair of arms having notches in their edges opening toward the other pair of arms, a rst bifurcated plate having the ends or" its legs in the notches of one pair of arms, a second bifurcated plate having the ends of its legs in the notches of the other pair of arms and extending around said iirst pair of arms, a tension spring connecting the closed ends of said plates, a compression spring acting on the closed end of said second plate for urging the toggle toward one of its operative positions, other arm means upstanding from said bracket, a terminal block mounted on said other arm means, and switch means mounted in said terminal block and positioned to be operated by said first plate when said second plate is moved against the thrust of said compression spring, spring means yieldably urging said switch means towards its closed position and means for adjusting the pressure differential between said compression spring and said spring means whereby predetermined amounts of pressure are required to open and close said switch means, said adjusting means including a stop member threadably mounted in said switch means and extending downwardly to abut said rst plate when the latter is in said operative position, and means for moving said stop member in and out of said switch means through an aperture in the top of said switch means.

Li. In a pressure switch, a toggle actuator comprising a bracket having spaced pairs of upstanding arms, the arms of each pair being spaced differently than the other pair, each said pair of arms having notches in their edges opening toward the other pair of arms, a rst bifurcated feo testfase 6 'plate having thefen'ds of its legs 'in the notches "of one pair vof arms, a second bifurcated plate having the endsof its vlegs-in the notches of ythe foth'er pair of arms 'and extending around said rs't pair of sarms, a tension spring connecting the *closed jends 'of said plates, a compression spring acting on the -closed 'end of said second plate `for"urging 'the-toggle'to-ward 'oneof its opye'rati've fpositions, *other 'arm "means lupstanding `from fsaid bracket, a terminal block mounted 'on said other armlmea'ns, and switch means mount- "ejd in "said terminal block and positioned Yto be -'o'pera'te'ol by -said first plateA when saidjsecond 4v'plate is moved against the thrust of Vsaid compression spring, spring means yieldably urging aids'witchmeans towards its closedlposition and jnieansfor adjusting the pressure differential bektween said compression spring and said spring means whereby predetermined amounts lof 'pressurejare required to open and-close said 4switch means, said adjusting means lincluding a stop member `tl'ireaoledly mounted in said switch 'means and extending downwardly to abut said rst plate when the'latter is in'said operative position, meanszfor movingsaid stop memberin and out of `said'sw'itclfi'means through an aperture in thetop'of saidswitch means and'means for varying'the amountof pressure 4exertedby saidcomv"pression spring against 'said 'second plate when 4said second plate isr init's said 'one operative positiOn.

5. In a pressure switch, a diaphragm, means for applying a variable pressure against said diaphragm, a switch means operatively connected to said diaphragm, means for opening said switch means at a rst predetermined pressure and for closing said switch at a second predetermined pressure, said last means comprising a bracket having spaced pairs of upstanding arms, the arms of each pair being spaced diierently than the other pair, each said pair of arms having notches in their edges opening toward the other pair of arms, a first bifurcated plate having the ends of its legs in the notches of one pair of arms, a sec- L) ond bifurcated plate having the ends of its legs in the notches of the other pair of arms and eX- tending around said rst pair of arms, a tension spring connecting the closed ends of said plates, a compression spring acting on the closed end of said second plate for urging the toggle toward one of its operative positions, means for varying the amount of compressive force exerted by said spring against said second plate when the latter is in said one operative position, other arm means upstanding from said bracket, a terminal block mounted on said other arm means, said switch means being mounted in said terminal block and positioned to be operated by said rst plate when said second plate is moved against the thrust of said compression spring, spring means yieldably urging said switch means towards its closed position.

6. In a pressure switch, a diaphragm, means for applying a variable pressure against said diaphragm, a switch means operatively connected to said diaphragm, means for opening said switch means at a rst predetermined pressure and for closing said switch at a second predetermined pressure, said last means comprising a bracket having spaced pairs of upstanding arms, the arms of each pair being spaced diierently than the other pair, each said pair of arms having notches in their edges opening toward the other pair of arms, a first bifurcated plate having the ends of its legs in the notches of one pair of arms, a second 'bifurcated plate having the ends of its legs in the notches of the other pair of arms and extending around said rst pair of arms, a tension spring connecting the closed ends of said plates, a compression spring acting on the closed end of said second plate for urging the toggle toward one of its operative positions, means for varying the amount of compressive force exerted by said spring against said second plate when the latter is in said one operative position, other arm means upstanding from said bracket, a terminal block mounted on said other arm means, said switch means being mounted in said terminal block and positioned to be operated by said rst plate when said second plate is moved against the thrust of said compression spring, spring means yieldably urging said switch means towards its closed position, and a stop member threadably mounted in said switch means and extending downwardly to abut said rst plate when the latter is in said operative position and means for moving said stop member in and out of said switch means through an aperture in the top of said switch means.

7. In a pressure switch, a diaphragm, means for applying a variable pressure against said diaphragm, a switch, means for operatively connect ing said diaphragm to said switch whereby variations in pressure will act to open and close said switch and means for adjusting the pressure differential between the open and closed positions of said switch, said connecting means comprising a bracket having spaced pairs of upstanding arms, the arms of each pair being spaced diierently than the other pair, each said pair of arms having notches in their edges opening toward the other pair of arms, a rst bifurcated plate having the ends of its legs in the notches of one pair of arms, a second bifurcated plate having the ends of its legs in the notches of the other pair of arms and extending around said first pair of arms, a tension spring connecting the closed ends of said plates, a compression spring acting on the closed end of said second plate for urging the toggle toward one of its operative positions, other arm means upstanding from said bracket, a terminal block mounted on said other arm means, and switch means mounted in said terminal block and positioned to be operated by said rst plate when said second plate is moved against the thrust of said compression spring, spring means yieldably urging said switch means towards its closed position.

H. HIX WOL'E. EDW'ARD W. HAAS.

References Cited in the file of this patent UNITED STATES PATENTS Number 

